This invention relates to an apparatus and a method for displaying a motion picture film on a television receiver, and in particular, provides an apparatus and a method for displaying a continuously moving motion picture film on a commercially available home television receiver.
Many systems have been proposed for displaying a motion picture film on a television receiver. Generally, these systems fall into two classes. First, there are more sophisticated and complex systems which are employed commercially, for example, by television networks and local television stations, for broadcasting a motion picture film. These commercial systems typically broadcast the motion picture film at a rate of twenty-four film frames per second for reception on a stardard home television receiver operating at thirty complete frames (or sixty half-frame fields) per second. The equipment typically operates by scanning, with one of the many well-known prior art systems, alternate film frames different numbers of times. For example, the conventional commercial equipment maintains synchronism between the film and the television by scanning a first film frame twice (corresponding to two television fields), the next or second film frame three times (corresponding to three television fields), the third film frame twice, and the fourth film frame three times. The sequence then repeats for the next four film frames. The commercial equipment scans each film frame in a time corresponding to a television field scan and thus displays each pair of successive film frames in five consecutive television fields.
The film frames are thus synchronized by the equipment to the television deflection signals. Typically, commercial systems of this type are electrically complex, expensive, and inflexible with respect to changing the film frame rate. The specific equipment used in this approach, such as the flying spot scanner which has a moving spot-like illumination source, are discussed in more detail in the "Television Engineering Handbood," edited by Donald J. Fink and published in 1957 by McGraw-Hill Book Co., Inc.
As an alternative to the foregoing commercial systems, which are priced beyond the reach of the average amateur photographer, a number of less expensive, more flexible, and electronically simpler systems have been proposed. At least one of these systems, as disclosed in Biber, U.S. Pat. No. 3,952,328, issued Apr. 20, 1976, modifies the standard color television receiver horizontal and vertical deflection timing to provide a television field scan rate which matches and is effectively "slaved" to the film frame rate of the motion picture. By thus coupling the display apparatus directly to the television receiver, the motion picture film may be advanced at an arbitrary frame rate. While the system is commercially acceptable, it requires modification of the electrical circuitry of the receiver, and this requirement often places it beyond the ability or desirability of the typical amateur photographer of movie film, as well as other potential users. Thus, the amateur photographer who considers his home television receive a logical display mechanism for motion pictures, and in particular home movies, continues to search for a simpler and less expensive motion picture projector which will display a motion picture film onto an unmodified home television receiver.
It is therefore a principle object of this invention to provide a low cost apparatus for displaying a motion picture film on a standard television receiver. Other objects of the invention are to provide an apparatus for displaying a motion picture film on a television receiver which can be adapted for use at more than one film frame rate, which can easily be operated by an amateur photographer, and which advantageously incorporates today's high technology semiconductor components. Further objects of the invention are to provide such an apparatus which are simple and reliable in operation.